66566597851 has 8 divisors (see below), whose sum is σ = 71689986144. Its totient is φ = 61443621120.

The previous prime is 66566597809. The next prime is 66566597857. The reversal of 66566597851 is 15879566566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66566597851 - 2²⁷ = 66432380123 is a prime.

It is a super-2 number, since 2×66566597851² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66566597857) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 288090 + ... + 464896.

It is an arithmetic number, because the mean of its divisors is an integer number (8961248268).

Almost surely, 2^66566597851 is an apocalyptic number.

66566597851 is a deficient number, since it is larger than the sum of its proper divisors (5123388293).

66566597851 is a wasteful number, since it uses less digits than its factorization.

66566597851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205781.

The product of its digits is 81648000, while the sum is 64.

The spelling of 66566597851 in words is "sixty-six billion, five hundred sixty-six million, five hundred ninety-seven thousand, eight hundred fifty-one".